The present invention pertains to pharmaceutical delivery devices, and, in particular, to a pharmaceutical delivery device having an automatic needle insert.
Patients suffering from a number of different diseases frequently must inject themselves with pharmaceuticals. As some patients find it difficult to insert a needle of an injector into one's skin, a variety of devices have been developed to facilitate this insertion task.
One type of such device automatically inserts a needle and then automatically injects a dose of medication through the inserted needle. With one version of this type device, after unlocking the device by manually twisting a handle, a patient needs to position the device against an injection site, and then operate a trigger of the device, such as by pressing the device firmly against the site. Trigger operation first causes a needled syringe within a housing of the device to shift such that its needle penetrates the skin, and then without further trigger operation or other user input, automatically causes a piston within the syringe to move to force the syringe contents through the inserted needle and into the patient. While this type of device may be useful for some patients, other patients may object to lacking control of the rate at which the injection process occurs.
Another known device disclosed in U.S. Pat. No. 5,980,491 mounts an injection pen therein and allows the needle of that pen to be automatically inserted into an injection site, whereafter the injection pen can be manually controlled to inject medication at a desired rate. However, because during needle insertion the injection pen is driven axially relative to the device, the patient may be startled or uncomfortable with the visible shifting of the pen, and further may have to readjust his or her hand to properly position a digit over the pen plunger before manually controlling the injection.
Thus, it would be desirable to provide a device that can overcome one or more of these and other shortcomings of the prior art.